Device aging is an irreversible process inherent to many, if not all, computer hardware and system technologies. Electromigration plays a role in the degradation of tungsten contacts between transistors, logic gates, interconnects, capacitors, resistors, inductors, and transistor delays. Power characteristics deteriorate as a consequence of Hotcarrier-Induced (HCI) and Negative Bias Temperature Instability (NBTI) effects. Mild overclocking and other events, such as fan failure, which may result in over temperature, and events where overvolting may take place in a server cause an immediate physical damage to the CPU (central processing unit) processor. High clock speeds, high temperatures, and over-voltages are known to accelerate the aging of transistors.
Common causes of failure due to aging include: (i) material fatigue; (ii) change in frequencies of crystal clocks; (iii) loss in ability of flash memory to rewrite data; (iv) changes in frequency response of fiber bandwidth; (v) de-magnetization of some components of magnetic disks; and (vi) dust build up. Simply stated, hardware components wear down over time.